The above identified '185 application relates to reusable and re-collapsible containers, and particularly to a one-piece container construction having a peripheral side wall which is arranged to include at least three sections of differential wall thickness and diameter to thereby permit movement of the container from an extended to a collapsed position by reason of a telescoping relationship between the various sections of the peripheral side wall. This continuation-in-part application is directed specifically to a novel interaction between the container and an associated cap which provides an added measure of resealability upon repeated uses of the cap.
Collapsible containers, drinking cups and the like are, of course, well known. For example, in applicant's own prior U.S. Pat. No. 4,930,644, a collapsible, thin film plastic container is disclosed wherein a major portion of the container side wall has a reduced wall thickness to permit random collapse of the side wall. In U.S. Pat. No. 4,865,211, a plastic bottle having a uniform wall thickness throughout the side wall, is configured to permit collapsing of the container through telescoping movement of one portion of the side wall into another portion of the side wall.
In U.S. Pat. No. 4,875,576, a container is disclosed wherein an intermediate portion of the side wall incorporates a bellows-type arrangement for facilitating collapse and extension of the container. The patent also discloses the use of helical creases which spiral or angle between first and second portions of the container side wall to facilitate collapsing action of the creased portion of the side wall.
In U.S. Pat. No. 4,873,100, a bi-stable, expandable plastic bottle is disclosed which incorporates a bellows-type side wall for movement between collapsed and extended positions.
In U.S. Pat. No. 2,880,902, a collapsible, drinking cup (or camera bellows) is disclosed wherein the side wall is composed of alternating thick and thin portions.
The present invention incorporates a number of features not previously found in the prior art and which result in simple, easy-to-use, low cost containers which may be used and reused by the consumer as desired, and which may be stored in a collapsed condition, maximizing storage space, etc. At the same time, by significantly reducing the thickness of the container side wall in an intermediate portion thereof, source reductions in the amount of plastic required to manufacture the containers are realized.
More specifically, the invention provides a one-piece, extruded and blow molded container formed with a peripheral side wall divided into upper, intermediate and lower portions, with the upper and lower portions having significantly greater wall thicknesses than the intermediate portion. For example, the intermediate portion may have a wall thickness of between about 2 and about 12 mil, and preferably about 8 rail, which permits the intermediate portion to reverse fold as the upper and lower portions, which may each have a wall thickness in the range of about 25-60 mil and preferably about 45 mil, are moved toward one another in the aforementioned telescoping relationship.
It is also a feature of the invention that the peripheral side wall include surface configurations which facilitate the axial collapse and extension of the container. Thus, in each of the disclosed embodiments, the intermediate peripheral side wall portion is formed with an inwardly and downwardly tapered profile, i.e., a decreasing diameter in the downward direction; and the lower peripheral side wall portion is formed with a downwardly and outwardly tapered profile, i.e., an increasing diameter in the downward direction. In addition, at the interface between the three sections, the changes in wall thickness provide a pair of annular steps which, in effect, provide a crease to facilitate the folding or collapsing action. The collapsing action is also facilitated by reason of the fact that the maximum and minimum diameters of the tapered intermediate side wall portion create a radial clearance between the lower edge of the upper side wall portion and the upper edge of the lower side wall portion, so that there is minimal frictional engagement between the upper, intermediate and lower side wall portions during collapsing and extending.
Another feature in each of the disclosed embodiments relates to the provision for a gripping area at the lower end of the lower portion of the peripheral side wall, particularly designed to facilitate the extension of the container from the collapsed position.
In an exemplary embodiment, the upper side wall portion of the container has a substantially uniform diameter in combination with a relatively rigid (but still flexible) annular rim. The rim itself may have the same or greater thickness dimensions than the upper and lower side wall portions.
In the exemplary embodiment, the upper end of the container, adjacent the rim edge, is provided with an external screw thread adapted to receive a screw-on type cap. In accordance with this continuation-in-part application, the surface adjacent the uppermost edge of the container rim is tapered downwardly and outwardly to provide, in effect, a beveled edge, for interaction with an associated cap, as described in greater detail below.
The unique cap construction in accordance with this invention includes a top wall and a radially outer depending skin provided with a screw thread on the internal surface of the skirt adapted to mate with the external screw thread provided on the upper end of the container. The cap construction is also formed with a radially inner depending skin which is adapted to engage the interior surface of the upper end of the container in order to support the latter in the manner described in the above identified parent application. The particularly unique aspect about the cap construction in accordance with this continuation-in-part application, relates to the interior surface configuration of the cap between the radially inner and outer depending skirts. This interior surface includes three surface portions. First, there is a substantially horizontal surface adjacent the radially inner annular skirt portion which extends radially outwardly where it intersects with a second downwardly and radially outwardly inclined surface which, in turn, merges with a third radiused surface which intersects the radially outer depending skirt. The second or inclined surface (which is substantially straight), provides a sealing area which is adapted to be sealingly engaged by the beveled upper edge of the container in such a manner that an axial space remains between the uppermost edge of the container and the first substantially horizontal surface of the cap adjacent the radially inner skirt.
By providing cooperating surfaces for engagement within a tapered sealing area in such a manner that an axial space remains between the top of the cap and the uppermost edge of the container, an effective seal may be effected repeatedly even though the uppermost edge of the container may not be substantially true, as is often the case in blow molded containers which are trimmed mechanically by mechanical cutters, slitters, etc. In addition, it will be appreciated that in light of the thin wall construction of the container, and the attendant flexibility thereof, there is a tendency for the container to flex radially, thereby causing the cap to bow upwardly and out of a normal sealing engagement. However, because of the seal effected along the mating tapered surfaces, even in the event the cap does bow upwardly, a seal will be maintained since the seal is, in effect, adjustable within the sealing area.
In addition, as the container is used and re-used, and as the cap is repeatedly secured and removed from the container, the cap will tend to draw closer to the upper edge of the container each time it is tightened. The unique seal arrangement in accordance with this invention also accommodates this tendency. This is because, already noted, the sealing action may occur at different locations within the sealing area along the mating tapered surfaces, throughout the useful life of the container.
Accordingly, in its broader aspects, the present invention relates to a container and associated cap assembly comprising a container body having an open upper end defined by an annular rim, the rim having a substantially horizontal uppermost edge surface and a radially outwardly and downwardly extending beveled surface; and a cap having a top wall, and a radially outer depending skirt, the radially outer depending skirt connected to the top wall by an internal cap surface which includes a downwardly and outwardly inclined surface portion which engages the bevelled surface such that the substantially horizontal uppermost edge surface is axially spaced from the cap top wall upon full threaded engagement between the cap and the container body.
Other objects and advantages of the subject invention will become apparent from the detailed description as follows.